A challenge in the exploration and treatment of internal areas of the human anatomy has been adequately visualizing the area of concern. Visualization can be especially troublesome in minimally invasive procedures in which small diameter, elongate instruments, such as catheters or endoscopes, are navigated through natural passageways of a patient to an area of concern either in the passageway or in an organ reachable through the passageway.
Ureteroscopy is one form of procedure that is performed to diagnosis and treat urinary tract diseases and ureteral strictures. In conventional ureterscopy, a ureteroscope is inserted retrograde through the urinary tract such that diagnosis and treatment of urinary tract abnormalities occur under direct visualization. Ureteroscopes are typically 7-10 Fr. in diameter and include a sheath that encapsulates a fiber optic element, an illumination element and a working channel. The working channel allows for the passage of working devices, such as guidewires, stone retrieval baskets and lasers. Some ureteroscopes also incorporate a steering mechanism, which allows the distal tip of the scope to be deflected by the user in one or more planes. Steering is typically achieved via manipulation at the handle end of the scope, ex-vivo.
Problems, however, exist in the use of prior art ureteroscopes. For example, after each successive urological procedure, the scope must be cleaned and sterilized before the next use, which delays successive procedures unless multiple scopes are purchased. Furthermore, current ureteroscopes are non-disposable and require extensive, expensive maintenance. Sterilization delays and costs associated with purchasing and/or repairing scopes have escalated costs for ureteroscopic procedures and other medical procedures that utilize similarly configured scopes.
Detailed information regarding other parts of the anatomy can be discerned from direct viewing of the anatomy provided through one or more of the elongate instruments used in other various medical procedures, such as colonoscopy, upper endoscopy, bronchoscopy, thoracoscopy, laparoscopy, and hysteroscopy. For use in these procedures, various types of endoscopes configured for use in various passageways of the body, such as the esophagus, rectum or bronchus, can be equipped with direct viewing capability through the use of optical fibers extending through the length of the scope, or with digital sensors, such as CCD or CMOS. However, because endoscopes also provide a working channel through which other medical instruments must pass, optional lighting bundles and components to provide steering capability at its distal end, the scope is typically of a relatively large diameter, e.g., 5 mm or greater. This large diameter limits the use of the endoscope to relatively large body lumens and prohibits their use in smaller ducts and organs that branch from a large body lumen, such as the biliary tree.
Typically when examining small passageway such as the bile duct or pancreatic duct, the endoscope is used to get close to a smaller passageway or region of concern and another instrument, such as a catheter, is then extended through the working channel of the endoscope and into the smaller passageway. Although the endoscope provides direct visualization of the large body passageway and entrance to adjoining ducts and lumens, after the smaller catheter has been extended from the endoscope into the smaller duct or lumen, direct visualization has heretofore been limited, and the physician usually relies on radiographical means to visualize the area of concern or probes blindly.